SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d11d229700990f4212aa68b61153edae69ee767a26926b34e42aa96d495145f' 
  AND token = 'R3VgOBnAKrJKEGWgirhW03rQCvF/8+xpqiwNnNGYhig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}